A corrosion-resistant current collector for lithium metal anodes

Due to its high theoretical specific capacity and negative electrochemical potential, Li is considered to be the ultimate choice for the battery anode. Unfortunately, poor Coulombic efficiency and uncontrolled dendrite growth prevent it from practical application. Electrolyte additives can effectively stabilize the solid electrolyte interphase (SEI) while utilizing various nanostructured forms of current collectors can decrease the current density and alleviate the volume fluctuation. Combining these two strategies could potentially lead to high performance Li metal anodes (LMAs). However, we found that Cu, the widely used anode current collector for lithium metal batteries, suffers corrosion in polysulfides containing electrolyte, which are proved to effectively protect the surface of Li anode in the study of Li-S batteries. Such corrosion could collapse the structure of LMAs. To mitigate the incompatibility of electrolyte additives and current collectors, we propose here a lightweight 3D Ti current collector that is corrosion-resistant in electrolyte with polysulfide additive. Outstanding Coulombic efficiency over 99% was achieved under high plating/stripping capacity of 5 mAh cm(-2) and no dendrite was observed. This work not only demonstrates an exceptional lightweight 3D current collector but also highlights the importance of the corrosion-resistance capability of the current collectors for LMAs.